1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * seqiv: Sequence Number IV Generator
  4 *
  5 * This generator generates an IV based on a sequence number by xoring it
  6 * with a salt.  This algorithm is mainly useful for CTR and similar modes.
  7 *
  8 * Copyright (c) 2007 Herbert Xu <herbert@gondor.apana.org.au>
 
 
 
 
 
 
  9 */
 10
 11#include <crypto/internal/geniv.h>
 12#include <crypto/scatterwalk.h>
 13#include <crypto/skcipher.h>
 14#include <linux/err.h>
 15#include <linux/init.h>
 16#include <linux/kernel.h>
 17#include <linux/module.h>
 18#include <linux/slab.h>
 19#include <linux/string.h>
 20
 
 
 21static void seqiv_aead_encrypt_complete2(struct aead_request *req, int err)
 22{
 23	struct aead_request *subreq = aead_request_ctx(req);
 24	struct crypto_aead *geniv;
 25
 26	if (err == -EINPROGRESS)
 27		return;
 28
 29	if (err)
 30		goto out;
 31
 32	geniv = crypto_aead_reqtfm(req);
 33	memcpy(req->iv, subreq->iv, crypto_aead_ivsize(geniv));
 34
 35out:
 36	kfree_sensitive(subreq->iv);
 37}
 38
 39static void seqiv_aead_encrypt_complete(struct crypto_async_request *base,
 40					int err)
 41{
 42	struct aead_request *req = base->data;
 43
 44	seqiv_aead_encrypt_complete2(req, err);
 45	aead_request_complete(req, err);
 46}
 47
 48static int seqiv_aead_encrypt(struct aead_request *req)
 49{
 50	struct crypto_aead *geniv = crypto_aead_reqtfm(req);
 51	struct aead_geniv_ctx *ctx = crypto_aead_ctx(geniv);
 52	struct aead_request *subreq = aead_request_ctx(req);
 53	crypto_completion_t compl;
 54	void *data;
 55	u8 *info;
 56	unsigned int ivsize = 8;
 57	int err;
 58
 59	if (req->cryptlen < ivsize)
 60		return -EINVAL;
 61
 62	aead_request_set_tfm(subreq, ctx->child);
 63
 64	compl = req->base.complete;
 65	data = req->base.data;
 66	info = req->iv;
 67
 68	if (req->src != req->dst) {
 69		SYNC_SKCIPHER_REQUEST_ON_STACK(nreq, ctx->sknull);
 70
 71		skcipher_request_set_sync_tfm(nreq, ctx->sknull);
 72		skcipher_request_set_callback(nreq, req->base.flags,
 73					      NULL, NULL);
 74		skcipher_request_set_crypt(nreq, req->src, req->dst,
 75					   req->assoclen + req->cryptlen,
 76					   NULL);
 77
 78		err = crypto_skcipher_encrypt(nreq);
 79		if (err)
 80			return err;
 81	}
 82
 83	if (unlikely(!IS_ALIGNED((unsigned long)info,
 84				 crypto_aead_alignmask(geniv) + 1))) {
 85		info = kmemdup(req->iv, ivsize, req->base.flags &
 86			       CRYPTO_TFM_REQ_MAY_SLEEP ? GFP_KERNEL :
 87			       GFP_ATOMIC);
 88		if (!info)
 89			return -ENOMEM;
 90
 
 91		compl = seqiv_aead_encrypt_complete;
 92		data = req;
 93	}
 94
 95	aead_request_set_callback(subreq, req->base.flags, compl, data);
 96	aead_request_set_crypt(subreq, req->dst, req->dst,
 97			       req->cryptlen - ivsize, info);
 98	aead_request_set_ad(subreq, req->assoclen + ivsize);
 99
100	crypto_xor(info, ctx->salt, ivsize);
101	scatterwalk_map_and_copy(info, req->dst, req->assoclen, ivsize, 1);
102
103	err = crypto_aead_encrypt(subreq);
104	if (unlikely(info != req->iv))
105		seqiv_aead_encrypt_complete2(req, err);
106	return err;
107}
108
109static int seqiv_aead_decrypt(struct aead_request *req)
110{
111	struct crypto_aead *geniv = crypto_aead_reqtfm(req);
112	struct aead_geniv_ctx *ctx = crypto_aead_ctx(geniv);
113	struct aead_request *subreq = aead_request_ctx(req);
114	crypto_completion_t compl;
115	void *data;
116	unsigned int ivsize = 8;
117
118	if (req->cryptlen < ivsize + crypto_aead_authsize(geniv))
119		return -EINVAL;
120
121	aead_request_set_tfm(subreq, ctx->child);
122
123	compl = req->base.complete;
124	data = req->base.data;
125
126	aead_request_set_callback(subreq, req->base.flags, compl, data);
127	aead_request_set_crypt(subreq, req->src, req->dst,
128			       req->cryptlen - ivsize, req->iv);
129	aead_request_set_ad(subreq, req->assoclen + ivsize);
130
131	scatterwalk_map_and_copy(req->iv, req->src, req->assoclen, ivsize, 0);
132
133	return crypto_aead_decrypt(subreq);
134}
135
136static int seqiv_aead_create(struct crypto_template *tmpl, struct rtattr **tb)
137{
138	struct aead_instance *inst;
139	int err;
140
141	inst = aead_geniv_alloc(tmpl, tb);
142
143	if (IS_ERR(inst))
144		return PTR_ERR(inst);
145
146	err = -EINVAL;
147	if (inst->alg.ivsize != sizeof(u64))
148		goto free_inst;
149
150	inst->alg.encrypt = seqiv_aead_encrypt;
151	inst->alg.decrypt = seqiv_aead_decrypt;
152
153	inst->alg.init = aead_init_geniv;
154	inst->alg.exit = aead_exit_geniv;
155
156	inst->alg.base.cra_ctxsize = sizeof(struct aead_geniv_ctx);
157	inst->alg.base.cra_ctxsize += inst->alg.ivsize;
158
159	err = aead_register_instance(tmpl, inst);
160	if (err) {
161free_inst:
162		inst->free(inst);
163	}
164	return err;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
165}
166
167static struct crypto_template seqiv_tmpl = {
168	.name = "seqiv",
169	.create = seqiv_aead_create,
 
170	.module = THIS_MODULE,
171};
172
173static int __init seqiv_module_init(void)
174{
175	return crypto_register_template(&seqiv_tmpl);
176}
177
178static void __exit seqiv_module_exit(void)
179{
180	crypto_unregister_template(&seqiv_tmpl);
181}
182
183subsys_initcall(seqiv_module_init);
184module_exit(seqiv_module_exit);
185
186MODULE_LICENSE("GPL");
187MODULE_DESCRIPTION("Sequence Number IV Generator");
188MODULE_ALIAS_CRYPTO("seqiv");

 
  1/*
  2 * seqiv: Sequence Number IV Generator
  3 *
  4 * This generator generates an IV based on a sequence number by xoring it
  5 * with a salt.  This algorithm is mainly useful for CTR and similar modes.
  6 *
  7 * Copyright (c) 2007 Herbert Xu <herbert@gondor.apana.org.au>
  8 *
  9 * This program is free software; you can redistribute it and/or modify it
 10 * under the terms of the GNU General Public License as published by the Free
 11 * Software Foundation; either version 2 of the License, or (at your option)
 12 * any later version.
 13 *
 14 */
 15
 16#include <crypto/internal/geniv.h>
 17#include <crypto/scatterwalk.h>
 18#include <crypto/skcipher.h>
 19#include <linux/err.h>
 20#include <linux/init.h>
 21#include <linux/kernel.h>
 22#include <linux/module.h>
 23#include <linux/slab.h>
 24#include <linux/string.h>
 25
 26static void seqiv_free(struct crypto_instance *inst);
 27
 28static void seqiv_aead_encrypt_complete2(struct aead_request *req, int err)
 29{
 30	struct aead_request *subreq = aead_request_ctx(req);
 31	struct crypto_aead *geniv;
 32
 33	if (err == -EINPROGRESS)
 34		return;
 35
 36	if (err)
 37		goto out;
 38
 39	geniv = crypto_aead_reqtfm(req);
 40	memcpy(req->iv, subreq->iv, crypto_aead_ivsize(geniv));
 41
 42out:
 43	kzfree(subreq->iv);
 44}
 45
 46static void seqiv_aead_encrypt_complete(struct crypto_async_request *base,
 47					int err)
 48{
 49	struct aead_request *req = base->data;
 50
 51	seqiv_aead_encrypt_complete2(req, err);
 52	aead_request_complete(req, err);
 53}
 54
 55static int seqiv_aead_encrypt(struct aead_request *req)
 56{
 57	struct crypto_aead *geniv = crypto_aead_reqtfm(req);
 58	struct aead_geniv_ctx *ctx = crypto_aead_ctx(geniv);
 59	struct aead_request *subreq = aead_request_ctx(req);
 60	crypto_completion_t compl;
 61	void *data;
 62	u8 *info;
 63	unsigned int ivsize = 8;
 64	int err;
 65
 66	if (req->cryptlen < ivsize)
 67		return -EINVAL;
 68
 69	aead_request_set_tfm(subreq, ctx->child);
 70
 71	compl = req->base.complete;
 72	data = req->base.data;
 73	info = req->iv;
 74
 75	if (req->src != req->dst) {
 76		SKCIPHER_REQUEST_ON_STACK(nreq, ctx->sknull);
 77
 78		skcipher_request_set_tfm(nreq, ctx->sknull);
 79		skcipher_request_set_callback(nreq, req->base.flags,
 80					      NULL, NULL);
 81		skcipher_request_set_crypt(nreq, req->src, req->dst,
 82					   req->assoclen + req->cryptlen,
 83					   NULL);
 84
 85		err = crypto_skcipher_encrypt(nreq);
 86		if (err)
 87			return err;
 88	}
 89
 90	if (unlikely(!IS_ALIGNED((unsigned long)info,
 91				 crypto_aead_alignmask(geniv) + 1))) {
 92		info = kmalloc(ivsize, req->base.flags &
 93				       CRYPTO_TFM_REQ_MAY_SLEEP ? GFP_KERNEL:
 94								  GFP_ATOMIC);
 95		if (!info)
 96			return -ENOMEM;
 97
 98		memcpy(info, req->iv, ivsize);
 99		compl = seqiv_aead_encrypt_complete;
100		data = req;
101	}
102
103	aead_request_set_callback(subreq, req->base.flags, compl, data);
104	aead_request_set_crypt(subreq, req->dst, req->dst,
105			       req->cryptlen - ivsize, info);
106	aead_request_set_ad(subreq, req->assoclen + ivsize);
107
108	crypto_xor(info, ctx->salt, ivsize);
109	scatterwalk_map_and_copy(info, req->dst, req->assoclen, ivsize, 1);
110
111	err = crypto_aead_encrypt(subreq);
112	if (unlikely(info != req->iv))
113		seqiv_aead_encrypt_complete2(req, err);
114	return err;
115}
116
117static int seqiv_aead_decrypt(struct aead_request *req)
118{
119	struct crypto_aead *geniv = crypto_aead_reqtfm(req);
120	struct aead_geniv_ctx *ctx = crypto_aead_ctx(geniv);
121	struct aead_request *subreq = aead_request_ctx(req);
122	crypto_completion_t compl;
123	void *data;
124	unsigned int ivsize = 8;
125
126	if (req->cryptlen < ivsize + crypto_aead_authsize(geniv))
127		return -EINVAL;
128
129	aead_request_set_tfm(subreq, ctx->child);
130
131	compl = req->base.complete;
132	data = req->base.data;
133
134	aead_request_set_callback(subreq, req->base.flags, compl, data);
135	aead_request_set_crypt(subreq, req->src, req->dst,
136			       req->cryptlen - ivsize, req->iv);
137	aead_request_set_ad(subreq, req->assoclen + ivsize);
138
139	scatterwalk_map_and_copy(req->iv, req->src, req->assoclen, ivsize, 0);
140
141	return crypto_aead_decrypt(subreq);
142}
143
144static int seqiv_aead_create(struct crypto_template *tmpl, struct rtattr **tb)
145{
146	struct aead_instance *inst;
147	int err;
148
149	inst = aead_geniv_alloc(tmpl, tb, 0, 0);
150
151	if (IS_ERR(inst))
152		return PTR_ERR(inst);
153
154	err = -EINVAL;
155	if (inst->alg.ivsize != sizeof(u64))
156		goto free_inst;
157
158	inst->alg.encrypt = seqiv_aead_encrypt;
159	inst->alg.decrypt = seqiv_aead_decrypt;
160
161	inst->alg.init = aead_init_geniv;
162	inst->alg.exit = aead_exit_geniv;
163
164	inst->alg.base.cra_ctxsize = sizeof(struct aead_geniv_ctx);
165	inst->alg.base.cra_ctxsize += inst->alg.ivsize;
166
167	err = aead_register_instance(tmpl, inst);
168	if (err)
169		goto free_inst;
170
171out:
172	return err;
173
174free_inst:
175	aead_geniv_free(inst);
176	goto out;
177}
178
179static int seqiv_create(struct crypto_template *tmpl, struct rtattr **tb)
180{
181	struct crypto_attr_type *algt;
182
183	algt = crypto_get_attr_type(tb);
184	if (IS_ERR(algt))
185		return PTR_ERR(algt);
186
187	if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & CRYPTO_ALG_TYPE_MASK)
188		return -EINVAL;
189
190	return seqiv_aead_create(tmpl, tb);
191}
192
193static void seqiv_free(struct crypto_instance *inst)
194{
195	aead_geniv_free(aead_instance(inst));
196}
197
198static struct crypto_template seqiv_tmpl = {
199	.name = "seqiv",
200	.create = seqiv_create,
201	.free = seqiv_free,
202	.module = THIS_MODULE,
203};
204
205static int __init seqiv_module_init(void)
206{
207	return crypto_register_template(&seqiv_tmpl);
208}
209
210static void __exit seqiv_module_exit(void)
211{
212	crypto_unregister_template(&seqiv_tmpl);
213}
214
215module_init(seqiv_module_init);
216module_exit(seqiv_module_exit);
217
218MODULE_LICENSE("GPL");
219MODULE_DESCRIPTION("Sequence Number IV Generator");
220MODULE_ALIAS_CRYPTO("seqiv");